Hybrid Alkoxysilane‐Gold Nanostructure Coatings on FTO Electrodes for Tailored Electrochemical Interfaces

Hybrid nanostructured interfaces represent a promising route toward advancing electrochemical materials and devices. In this study, fluorine‐doped tin oxide (FTO) electrodes were modified with alkoxysilanes – 3‐aminopropyltrimethoxysilane (APTMS) and 3‐mercaptopropyltrimethoxysilane (MPTMS) – in combination with gold nanostructures, including gold nanoparticles (AuNPs) and silica‐coated gold nanoparticles (Au@SiO ₂ ). The synergy between molecular surface modifiers and nanostructures was systematically evaluated using cyclic voltammetry and electrochemical impedance spectroscopy. The results revealed distinct contributions of the modifiers: MPTMS impeded electron transfer, APTMS partially supported redox processes, whereas the incorporation of AuNPs or Au@SiO ₂ markedly enhanced charge–transfer efficiency. Among all tested configurations, the APTMS/Au@SiO ₂ ‐modified electrode exhibited the most favorable electrochemical performance, achieving significantly improved sensitivity for dopamine detection. These findings underline the importance of interfacial nanostructure design, demonstrating that hybrid alkoxysilane‐gold coatings not only promote efficient electron transport but also provide mechanical and chemical robustness. The demonstrated strategy provides a versatile framework for engineering stable and functional nanomaterial‐based electrodes.